In a turn signal switch device of vehicles, a base portion of a control lever is supported by a holder so as to be tilted along one plane, and the holder is supported by a housing fixed to a steering column or the like so as to be tilted integrally with the control lever along the other plane which substantially crosses the one plane at right angles. Further, when a lever portion of the control lever is tilted to any one of left and right direction indication positions along the other plane from a neutral position, a lamp for left or right turn is switched on and off. When the lever portion of the control lever is tilted along the one plane, a beam switching or passing operation is performed. In such a turn signal switch device, in order for the control lever to smoothly move between the neutral position and the left and right direction indication positions, a spring member and a driving body are interposed between a cam surface provided in the housing side and the holder such that the driving body comes in elastic contact with the cam surface. Similarly, in order for the control lever to smoothly move between a beam switching position or passing position and the neutral position, the spring member and the driving body are also interposed between the cam surface provided in the holder side and the base portion of the control lever such that the driving body comes in elastic contact with the cam surface.
Hereinafter, the structure of a conventional turn signal switch device (for example, refer to Japanese Unexamined Patent Application Publication No. 2001-6495 (Pages 4-7, FIG. 1)) will be described with reference to FIGS. 8 to 10. FIG. 8 is an exploded perspective view of a conventional turn signal switch device. FIG. 9 is a bottom view of a cancel mechanism of the turn signal switch device. FIG. 10 is a diagram for explaining an operation of the cancel mechanism.
In the drawings, the turn signal switch device includes first and second cases 101 and 102 which are formed of synthetic resin and compose a housing, a control lever 103 supported by both of the cases 101 and 102 through a holder 108, first and second lever members 104 and 105 loaded on the inner surface of the second case 102, and a torsion coil spring 106 which elastically biases the first lever member 104 in a direction where the first lever member 104 projects to the outside of the second case 102. However, an operating member 107 is fixed to a base portion of the control lever 103, and a movable member 109 is swingably supported by the holder 108. Further, the first and second cases 101 and 102 are integrated through snapping or the like, and are fixed to a stator member such as a column cover or combination switch (not shown).
The first case 101 has a V-shaped cam surface 110 provided on the inner surface thereof, the cam surface 110 having a valley portion and a lock portion. A first driving body 124, which is held by the holder 108 and is biased by a spring 125, comes in elastic contact with the cam surface 110 so as to slide thereon. Further, a printed board (not shown) is attached on the inner bottom portion of the first case 101, and contact portions for lighting lamps are arranged on the printed board.
On the inner surface of the second case 102, a guide shaft 116 and a support shaft 117 are erected on the same line, and a boss 119 is erected. The guide shaft 116 rotatably and slidably supports the first lever member 104, and the support shaft 117 rotatably supports the second lever member 105. Further, the boss 119 supports the wound portion of the torsion coil spring 106.
The first and second lever members 104 and 105 are connected by engaging a connection pin 105d with a long hole 104b. The first lever member 104 has long holes 104a and 104b and a spring receiving portion 104c provided therein. As the guide shaft 116 is inserted into the long hole 104a, the lever member 104 is rotatably and slidably supported. Further, an abutting portion 104d is provided on one longitudinal end of the first lever member 104, and a cam engagement portion 104e is erected on the other longitudinal end. Meanwhile, the second lever member 105 has first and second openings 121 and 122 and an attachment hole 105a provided therein. As the support shaft 117 is inserted into the attachment hole 105a, the lever member 105 is rotatably supported. Further, a projecting portion 105c and the connection pin 105d are provided at one longitudinal end of the second lever member 105. In a state where the connection pin 105d is inserted into and linked with the long hole 104b, both of the lever members 104 and 105 overlap each other.
The torsion coil spring 106 has an arm portion 106c extending in a cantilever shape, and the arm portion 106c is engaged with the spring receiving portion 104c of the first lever member 104. Therefore, the first lever member 104 is elastically biased in a direction where the abutting portion 104d is pressed outward along the long holes 104a and 104b. 
The operating member 107 fixed to the root portion of the control lever 103 forms the base portion of the control lever 103. The operating member 107 is formed of synthetic resin, and a circular concave portion 107a is provided on both side surfaces thereof. Further, the holder 108 has a pair of projection pieces 108a such that the operating member 107 is interposed between the projection pieces 108a, and each of the projection pieces 108a has a cylindrical projection 108b provided on the inner surface thereof. The holder 108 is also formed of synthetic resin. Through snapping where the respective projections 108b are fitted into the circular concave portions 107a, the base portion (operating member 107) of the control lever 103 is supported by the holder 108. At the end of the holder 108 opposite the projection piece 108a, a cam surface 108c is formed. The cam engagement portion 104e of the first lever 104 comes in sliding contact with the cam surface 108c. Although not shown, a separate cam surface is also formed within the holder 108, and a second driving body 127, which is held by the operating member 107 and is biased by a spring 126, comes in elastic contact with the cam surface so as to slide thereon. The holder 108 has a pair of support shafts 108d and 108e projecting thereon. As the support shafts 108d and 108e are fitted into the bearing portions of the first and second cases 101 and 102, the holder 108 is supported by both of the cases 101 and 102. However, the axial direction of the support shafts 108d and 108e is set to substantially cross the axial direction of the protrusion 108b at right angles. Accordingly, with the support shafts 108d and 108e being set to a rotating shaft, the control lever 103 and the operating member 107 can be tilted integrally with the holder 108 along one plane with respect to both of the cases 101 and 102. Further, with the protrusion 108b being set to a rotating shaft, the control lever 103 and the operating member 107 can be tilted along the other plane, which substantially crosses the one plane at right angles, with respect to the holder 108 and both of the cases 101 and 102.
In a state where the movable member 109 is inserted into an opening 108g of the holder 108 and is biased by a spring 125, the movable member 109 is attached to the holder 108 so as to slightly swing. The movable member 109 has a receiving portion 109e projecting thereon, the receiving portion 109e being disposed in the second opening 122 of the second lever member 105. The receiving portion 109e is disposed in a curved edge 122a of the second opening 122.
Now, an operation of the conventional turn signal switch device constructed in such a manner will be described. First, when the control lever 103 is located at a neutral position, the first driving body 124 comes in elastic contact with the valley portion of the cam surface 110. Therefore, the control lever 103 is held at the neutral position. At this time, the cam engagement portion 104e of the first lever member 104 is abutted on the top portion of the cam surface 108c of the holder 108 such that the position thereof is restricted. Therefore, as shown in FIG. 10A, the first lever member 104 is held within the second case 102 against the biasing force of the torsion coil spring 106. Further, the abutting portion 104d is positioned outside a rotational locus of the cancel projection 128 which is rotated with a steering wheel of a vehicle.
When the control lever 103 located at the neutral position is tilted to any one of left and right direction indication positions with the support shafts 108d and 108e set to a rotating shaft, the first driving body 124 slides on the cam surface 110 so as to generate click feeling and is then held by the lock portion. Further, the holder 108 and the movable member 109 are rotated at a predetermined angle in the same direction such that the top portion of the cam surface 108c is separated from the cam engagement portion 104e. Further, as shown in FIG. 10B, the first lever member 104 is moved toward the one longitudinal end by the biasing force of the torsion coil spring 106, and the abutting portion 104d enters the rotational locus of the cancel projection 128. In this state, since a steering wheel is rotationally controlled in the same direction as the tilt direction of the control lever 103, the cancel projection 128 can be abutted on the abutting portion 104d in the reverse direction to an arrow direction of FIG. 10B. However, although the cancel projection 128 is abutted in this direction such that the first and second lever members 104 and 105 rotates in the counterclockwise direction, the torque is not transmitted to the receiving portion 109e of the movable member 109. Therefore, when the cancel projection 128 passes, both of the lever members 104 and 105 returns to the state of FIG. 10B due to the biasing force of the torsion coil spring 106.
In this state, however, when the steering wheel is rotationally controlled in the reverse direction to the tilt direction of the control lever 103, the cancel protrusion 128 is abutted on the abutting portion 104d in the arrow direction of FIG. 10B. Therefore, the first and second lever members 104 and 105 are rotated in the clockwise direction. That is, since the first lever member 104 is rotationally driven in the clockwise direction about the guide shaft 116, the second lever member 105 is rotated with the rotation of the first lever member 104, and the curved edge 122a of the second opening 122 pushes the receiving portion 109e of the movable member 109 upward in the drawing. Since the pushing force is transmitted to the holder 108 from the movable member 109, the first driving body 124 is separated from the lock portion of the cam surface 110 so as to be pushed back to the valley portion. Further, both of the lever members 104 and 105 automatically return to the neutral position shown in FIG. 10A.
In the state of FIG. 10B, when any force preventing the automatic return acts on the control lever 103, for example, when the steering wheel is rotationally controlled in the reverse direction to the tilt direction while the control lever 103 is pushed by the hand, the receiving portion 109e is pressed along the curved edge 122a by a divided force of the torque of the second lever member 105, as shown in FIG. 10C. Therefore, the movable member 109 slightly swings with respect to the holder 108, against the biasing force of the spring 125. Further, the first and second lever members 104 and 105 can be rotated without being hindered by the receiving portion 109e. 
Meanwhile, when the control lever 103 located at the neutral position is tilted with the protrusion 108b set to a rotating shaft, the operating member 107 forming the base portion of the control lever 103 is rotated at a predetermined angle in the same direction with respect to the holder 108. Therefore, the second driving body 127 slides on a cam surface (not shown) formed in the holder 108. As a result, when the control lever 103 is tilted in one direction, click feeling is generated, so that a beam switching operation is performed. Alternately, when the control lever 103 is tilted in the reverse direction, a passing operation is performed.
FIG. 11 shows another conventional turn signal switch device. In the conventional turn signal switch device shown in FIG. 11, a holder 201 supported by a case (not shown) and a base portion 203 of a control lever 202 are rotatably connected to each other by using a shaft 204 and a retaining member 205 (for example, refer to Japanese Unexamined Patent Application Publication No. 2006-221933(Pages 6-12, FIG. 2)). In the conventional turn signal switch device, the base portion 203 of the control lever 202 is inserted into an opening 201a of the holder 201, and the shaft 204 with excellent rigidity is inserted into a shaft hole 203a provided in the base portion 203 and a bearing hole 201c provided in a pair of side plates 201b of the holder 201 facing each other through the opening 201a. Then, the retaining member 205 such as a washer or the like is fitted into one end of the shaft 204. The other end of the shaft 204 is formed with a head 204a having a larger diameter than those of the shaft hole 203a and the bearing hole 201c. Therefore, as the head 204a and the retaining member 205 are positioned outside the side plates 201b of the holder 201, the base portion 203 of the control lever 202 can be reliably connected to the holder 201, with the shaft 204 being set to a rotating shaft.
However, in the conventional turn signal switch device disclosed in Japanese Unexamined Patent Application Publication No. 2001-6495, the holder 108 supported by the first and second cases 101 and 102 and the operating member 107 forming the base portion of the control lever 103 are rotatably connected to each other through the snapping in which the protrusion 108b of the holder 108 is fitted into the circular concave portion 107a of the operating member 107. Therefore, there are difficulties in increasing connection strength between the holder 108 and the operating member 107. That is, to improve control feeling during the tilting of the control lever 103, the springs 125 and 126 which cause the first and second driving bodies 124 and 127 to come in elastic contact with the respective cam surfaces need to generate a predetermined elastic repulsive force such that the control lever 103 does not lack an operation force. However, when the elastic repulsive force generated by the springs 125 and 126 is large, the projection 108b of the holder 108 is easily separated from the circular concave portion 107a of the operating member 107 by the reaction force.
In the conventional turn signal switch device disclosed in Japanese Unexamined Patent Application Publication No. 2006-221933, the holder 201 supported by the case and the base portion 203 of the control lever 202 are rotatably connected to each other by using the shaft 204 and the retaining member 205. Therefore, although the operating force of the control lever 202 is strengthened, it is not likely that the connection strength between the holder 201 and the base portion 203 is insufficient. However, since two members such as the shaft 204 and the retaining member 205 should be added, the number of components increases. Further, since the retaining member 205 such as a washer should be fitted into one end of the shaft 204, an assembling property is degraded.
The present invention has been finalized in view of the drawbacks inherent in the conventional antenna, and it is an object of the present invention to provide a turn signal switch device, in which although an operation force of a control lever is set to predetermined strength, a base portion of the control lever is not separated from a holder, an assembling property is excellent, and the number of components is prevented from increasing.